Blend thoroughly the cheese, egg yolks, sugar, cinnamon and salt. Add the yogurt to make a thick paste. Add the melted butter or margarine. Stir in the flour. Beat the egg whites stiff and fold into the mixture. Pour into a greased quart casserole. Set the casserole into a shallow pan of water and bake uncovered in a 350F Oven for 1 hour. chill. May be served with more yogurt. Serves 4 - 6
